(function(){
  'use strict';

  /*
  * Add integers, wrapping at 2^32. This uses 16-bit operations internally
  * to work around bugs in some JS interpreters.
  */
  function safe_add(x, y) {
      var lsw = (x & 0xFFFF) + (y & 0xFFFF),
          msw = (x >> 16) + (y >> 16) + (lsw >> 16);
      return (msw << 16) | (lsw & 0xFFFF);
  }

  /*
  * Bitwise rotate a 32-bit number to the left.
  */
  function bit_rol(num, cnt) {
      return (num << cnt) | (num >>> (32 - cnt));
  }

  /*
  * These functions implement the four basic operations the algorithm uses.
  */
  function md5_cmn(q, a, b, x, s, t) {
      return safe_add(bit_rol(safe_add(safe_add(a, q), safe_add(x, t)), s), b);
  }
  function md5_ff(a, b, c, d, x, s, t) {
      return md5_cmn((b & c) | ((~b) & d), a, b, x, s, t);
  }
  function md5_gg(a, b, c, d, x, s, t) {
      return md5_cmn((b & d) | (c & (~d)), a, b, x, s, t);
  }
  function md5_hh(a, b, c, d, x, s, t) {
      return md5_cmn(b ^ c ^ d, a, b, x, s, t);
  }
  function md5_ii(a, b, c, d, x, s, t) {
      return md5_cmn(c ^ (b | (~d)), a, b, x, s, t);
  }

  /*
  * Calculate the MD5 of an array of little-endian words, and a bit length.
  */
  function binl_md5(x, len) {
      /* append padding */
      x[len >> 5] |= 0x80 << (len % 32);
      x[(((len + 64) >>> 9) << 4) + 14] = len;

      var i, olda, oldb, oldc, oldd,
          a =  1732584193,
          b = -271733879,
          c = -1732584194,
          d =  271733878;

      for (i = 0; i < x.length; i += 16) {
          olda = a;
          oldb = b;
          oldc = c;
          oldd = d;

          a = md5_ff(a, b, c, d, x[i],       7, -680876936);
          d = md5_ff(d, a, b, c, x[i +  1], 12, -389564586);
          c = md5_ff(c, d, a, b, x[i +  2], 17,  606105819);
          b = md5_ff(b, c, d, a, x[i +  3], 22, -1044525330);
          a = md5_ff(a, b, c, d, x[i +  4],  7, -176418897);
          d = md5_ff(d, a, b, c, x[i +  5], 12,  1200080426);
          c = md5_ff(c, d, a, b, x[i +  6], 17, -1473231341);
          b = md5_ff(b, c, d, a, x[i +  7], 22, -45705983);
          a = md5_ff(a, b, c, d, x[i +  8],  7,  1770035416);
          d = md5_ff(d, a, b, c, x[i +  9], 12, -1958414417);
          c = md5_ff(c, d, a, b, x[i + 10], 17, -42063);
          b = md5_ff(b, c, d, a, x[i + 11], 22, -1990404162);
          a = md5_ff(a, b, c, d, x[i + 12],  7,  1804603682);
          d = md5_ff(d, a, b, c, x[i + 13], 12, -40341101);
          c = md5_ff(c, d, a, b, x[i + 14], 17, -1502002290);
          b = md5_ff(b, c, d, a, x[i + 15], 22,  1236535329);

          a = md5_gg(a, b, c, d, x[i +  1],  5, -165796510);
          d = md5_gg(d, a, b, c, x[i +  6],  9, -1069501632);
          c = md5_gg(c, d, a, b, x[i + 11], 14,  643717713);
          b = md5_gg(b, c, d, a, x[i],      20, -373897302);
          a = md5_gg(a, b, c, d, x[i +  5],  5, -701558691);
          d = md5_gg(d, a, b, c, x[i + 10],  9,  38016083);
          c = md5_gg(c, d, a, b, x[i + 15], 14, -660478335);
          b = md5_gg(b, c, d, a, x[i +  4], 20, -405537848);
          a = md5_gg(a, b, c, d, x[i +  9],  5,  568446438);
          d = md5_gg(d, a, b, c, x[i + 14],  9, -1019803690);
          c = md5_gg(c, d, a, b, x[i +  3], 14, -187363961);
          b = md5_gg(b, c, d, a, x[i +  8], 20,  1163531501);
          a = md5_gg(a, b, c, d, x[i + 13],  5, -1444681467);
          d = md5_gg(d, a, b, c, x[i +  2],  9, -51403784);
          c = md5_gg(c, d, a, b, x[i +  7], 14,  1735328473);
          b = md5_gg(b, c, d, a, x[i + 12], 20, -1926607734);

          a = md5_hh(a, b, c, d, x[i +  5],  4, -378558);
          d = md5_hh(d, a, b, c, x[i +  8], 11, -2022574463);
          c = md5_hh(c, d, a, b, x[i + 11], 16,  1839030562);
          b = md5_hh(b, c, d, a, x[i + 14], 23, -35309556);
          a = md5_hh(a, b, c, d, x[i +  1],  4, -1530992060);
          d = md5_hh(d, a, b, c, x[i +  4], 11,  1272893353);
          c = md5_hh(c, d, a, b, x[i +  7], 16, -155497632);
          b = md5_hh(b, c, d, a, x[i + 10], 23, -1094730640);
          a = md5_hh(a, b, c, d, x[i + 13],  4,  681279174);
          d = md5_hh(d, a, b, c, x[i],      11, -358537222);
          c = md5_hh(c, d, a, b, x[i +  3], 16, -722521979);
          b = md5_hh(b, c, d, a, x[i +  6], 23,  76029189);
          a = md5_hh(a, b, c, d, x[i +  9],  4, -640364487);
          d = md5_hh(d, a, b, c, x[i + 12], 11, -421815835);
          c = md5_hh(c, d, a, b, x[i + 15], 16,  530742520);
          b = md5_hh(b, c, d, a, x[i +  2], 23, -995338651);

          a = md5_ii(a, b, c, d, x[i],       6, -198630844);
          d = md5_ii(d, a, b, c, x[i +  7], 10,  1126891415);
          c = md5_ii(c, d, a, b, x[i + 14], 15, -1416354905);
          b = md5_ii(b, c, d, a, x[i +  5], 21, -57434055);
          a = md5_ii(a, b, c, d, x[i + 12],  6,  1700485571);
          d = md5_ii(d, a, b, c, x[i +  3], 10, -1894986606);
          c = md5_ii(c, d, a, b, x[i + 10], 15, -1051523);
          b = md5_ii(b, c, d, a, x[i +  1], 21, -2054922799);
          a = md5_ii(a, b, c, d, x[i +  8],  6,  1873313359);
          d = md5_ii(d, a, b, c, x[i + 15], 10, -30611744);
          c = md5_ii(c, d, a, b, x[i +  6], 15, -1560198380);
          b = md5_ii(b, c, d, a, x[i + 13], 21,  1309151649);
          a = md5_ii(a, b, c, d, x[i +  4],  6, -145523070);
          d = md5_ii(d, a, b, c, x[i + 11], 10, -1120210379);
          c = md5_ii(c, d, a, b, x[i +  2], 15,  718787259);
          b = md5_ii(b, c, d, a, x[i +  9], 21, -343485551);

          a = safe_add(a, olda);
          b = safe_add(b, oldb);
          c = safe_add(c, oldc);
          d = safe_add(d, oldd);
      }
      return [a, b, c, d];
  }

  /*
  * Convert an array of little-endian words to a string
  */
  function binl2rstr(input) {
      var i,
          output = '';
      for (i = 0; i < input.length * 32; i += 8) {
          output += String.fromCharCode((input[i >> 5] >>> (i % 32)) & 0xFF);
      }
      return output;
  }

  /*
  * Convert a raw string to an array of little-endian words
  * Characters >255 have their high-byte silently ignored.
  */
  function rstr2binl(input) {
      var i,
          output = [];
      output[(input.length >> 2) - 1] = undefined;
      for (i = 0; i < output.length; i += 1) {
          output[i] = 0;
      }
      for (i = 0; i < input.length * 8; i += 8) {
          output[i >> 5] |= (input.charCodeAt(i / 8) & 0xFF) << (i % 32);
      }
      return output;
  }

  /*
  * Calculate the MD5 of a raw string
  */
  function rstr_md5(s) {
    return binl2rstr(binl_md5(rstr2binl(s), s.length * 8));
  }


  /*
  * Convert a raw string to a hex string
  */
  function rstr2hex(input) {
      var hex_tab = '0123456789abcdef',
          output = '',
          x,
          i;
      for (i = 0; i < input.length; i += 1) {
          x = input.charCodeAt(i);
          output += hex_tab.charAt((x >>> 4) & 0x0F) +
              hex_tab.charAt(x & 0x0F);
      }
      return output;
  }

  /*
  * Encode a string as utf-8
  */
  function str2rstr_utf8(input) {
      return unescape(encodeURIComponent(input));
  }

  /*
  * Take string arguments and return either raw or hex encoded strings
  */
  function raw_md5(s) {
      return rstr_md5(str2rstr_utf8(s));
  }

  function hex_md5(s) {
      return rstr2hex(raw_md5(s));
  }

  /**
   * Md5
   */
  function md5(message, salt) {
    if (salt !== undefined && salt !== null && salt !== ''){
      message = message + '{' + salt + '}'
    }
    return hex_md5(message);
  }

  
	module.exports = function (message, key) {
		if (message === undefined || message === null)
		  throw new Error('Illegal argument ' + message);
		return md5(message, key);
	  
	};

    
})();
